Please, do not forget to SHOW ALL YOUR WORK and Calculations and Also explain your answers.

Total: 8 questions.

Questions:

1. Consider a plane of mass 50,000 kg in takeoff when the thrust for each of its four engines is 25,000 N. If the plane is facing an air drag force of 10,000 N; What is the acceleration of the plane?

2. Peter, who has a mass of 80 Kg is skateboarding at 5 m/s when he smacks into a brick wall and comes to a dead stop in 0.25 sec. What is his acceleration? What is the force acting on him?

3. A boxer punches a sheet of paper in midair and bring it from rest up to a speed of 20 m/s in in 0.02 sec. Mass of paper is 0.005 Kg.

a.What acceleration is imparted to the paper?

b.What force does the boxer exert on it?

c. What force does the paper exert on the boxer?

4. If you stand next to a wall on a frictionless skateboard and push the wall with a force of 40 N, how hard does the wall push on you? If your mass is 75 Kg, what will be your acceleration?

5. What average net force is required to bring a 1200 kg car to rest from a speed of 25 m/s (90 km/h) in 10 seconds?

6. A 50 Kg toolbox is being push along the floor by a 100 N horizontal force. Friction between the floor surface and the box is 20 N. What is the acceleration of the box?

7. An igneous rock has a mass of 5 Kg.

a. What is its weight on the moon, where the acceleration due to gravity is one sixth that on Earth?

b. What is ist weight in Jupiter, where the acceleration due to gravity is 2.64 times that on Earth?

8. A 0.2 kg ball is thrown upward with and initial speed of 10 m/s.

a. What is the force acting on the ball when it reaches half of its maximum height?

b. What is the force on the ball when it reaches its peak?